Keypads are important aspects of computing devices. With regard to small form-factor keypads in particular, the keypads tend to establish the overall form-factor of a computing device. The keypad is often a very visible and highly used component of such computing devices.
Messaging devices, in particular, have need for QWERTY style keyboards. Such keyboards are often operated by the user using thumbs. Key size, visibility, and sensation are important characteristics for consideration in the design of small form-factor keyboards. One further consideration is usability of such features in darkened environment. Many users typically need to see some or all keys of a keyboard when thumb typing on a small form factor keyboard, as such devices have closely spaced keys that may require visual coordination.